What is studied is a system which lives in the minds of economists but not on earth. I have called the result “blackboard economics.” The firm and th… - Ronald Coase

The question always is, will it pay to bring an extra exchange transaction under the organizing authority? At the margin, the costs of organizing within the firm will be equal either to the costs of organizing in another firm or to the costs involved in leaving the transaction to be “organised” by the price mechanism. Business men will be constantly experimenting, controlling more or less, and in this way equilibrium will be maintained. This gives the position of equilibrium for static analysis.

Economists have uncovered the conditions necessary if Adam Smith’s results are to be achieved and where, in the real world, such conditions do not appear to be found, they have proposed changes which are designed to bring them about. It is what one finds in the textbooks. Harold Demsetz has said rightly that what this theory analyses is a system of extreme decentralisation. It has been a great intellectual achievement and it throws light on many aspects of the economic system. But it has not been by any means all gain.

In my youth it was said that what was too silly to be said may be sung. In modern economics it may be put into mathematics.